The present invention relates to a rotor having a consequent pole type structure and a motor including such a rotor.
Japanese Laid-Open Patent Publication No. 9-327139 discloses a rotor having the so-called consequent pole type structure as one example of a rotor used in a motor. The rotor described in the publication includes a plurality of magnets, which are arranged in a circumferential direction of a rotor core, and salient poles, which are arranged between the magnets and formed integrally with the rotor core. The plurality of magnets function as one magnetic pole, and the plurality of salient poles function as the other magnetic pole.
The rotor having the consequent pole type structure that is disclosed in the publication includes the magnets, which generate a magnetic flux, and the salient poles, which do not generate a magnetic flux. Thus, there is a tendency for a magnetic unbalance to occur in the consequent pole type structure rotor. This increases torque ripple or the like and thereby lowers the rotation performance.